What is nagling? How can I disable this?

The application of Nagle's Algortihm (named after its inventor, John Nagle) is commonly known as nagling. Nagling basically concatenates a number of small buffer messages thus decreasing the number of packets that must be sent across the network and is usually enabled by default.

Sometimes, you may want to disable nagling for some higly interactive applications and real-time systems and this may be done through the use of the TCP_NODELAY sockets option.